1. Field of the Invention
The present invention relates to a water vehicle and in particular to a kayak having a louvered rockered hull which improves the speed and maneuverability of said kayak.
2. Description of the Prior Art
Two most important aspects of a kayak are its speed and maneuverability. Speed or maneuverability but not both is a common trade-off associated with kayaks. Speed is an issue as kayaks are propelled on water by the occupant with the use of a paddle.
In the case of a whitewater kayak; maneuverability is more important than speed. For this reason whitewater kayaks have a significantly rockered hull. The rockered hull has high profile ends which increase its turning ability leading to increased maneuverability. Whitewater kayaks are said to have displacement hulls that are very close to planing hulls. Nonetheless, fast whitewater kayak are sought after.
Several aspects affect the forward speed of a kayak:
the energy required to displace the water at the leading end of the kayak, PA1 how the molecules travel along the length of the hull, PA1 how water returns to its original position once the kayak has passed by, and PA1 the amount of wetted surface area.
Thus energy conservation is important when considering the motion of a kayak through water.
The energy required to displace a water molecule can be significantly reduced by increasing the waterline of the kayak. By increasing the length of the hull, the displacement of the water molecule to its final position can be spread over a greater distance. This modification has to be weighed against the resulting increase in the effective wetted surface area of the kayak coming from the increase in length. This increase in the waterline could slow the kayak down if the induced drag by the wetted surface area is disproportional to the increased effectiveness of displacement.
Another feature of the kayak that affects the motion of water molecules past the kayak is the profile of its bow at the moment of entry. A sleeker bow is more efficient at moving the molecules to the side, but it also increases resistance to sideways movement of the kayak which reduces the kayak's turning ability. Similarly a sleeker stern is more efficient in guiding the movement of the water molecules as they return to their original position, but as above mentioned, it also reduces the kayak's turning ability. A rockered bow and stern allows the kayak to turn easier but, at the same time, this shortens the effective waterline length of the kayak thereby offering a less effective profile for displacing water.
It would be advantageous to provide whitewater kayaks with speed enhancing features.